This Gothic cathedral dates from the 14th century, though its huge 60m tower was only added in 1596. As in Olsztyn's castle, the most impressive architectural feature is the webbed vaulting in the aisles, reminiscent of Gaudí’s Sagrada Família in Barcelona. The nave, however, has netlike arches dating from the 17th century. Among the remarkable works of art are the 16th-century triptych at the head of the left aisle, and a shimmering gold and silver altarpiece of the Virgin Mary.